Named for Thomas Moran, one of America's great landscape painters (www.nga.gov/feature/moran/index.shtm ), Mount Moran is also one of the most photogenic of the peaks in the Teton Range. It is also one of the most interesting geologically. The vast bulk of the mountain is Archean granitoids and gneisses, but they are cut by an enormous (200 foot wide) basaltic dike (the aptly named "Black Dike") of Late Proterozoic age. Furthermore, the mountain is capped by a tiny remnant of Cambrian Flathead Sandstone that constrains both the age of the dike and the amount of total vertical displacement on the active, range-front, Teton normal fault.